As Voice over Internet Protocol (or Voice over IP) telephony has proliferated, so have unwanted, automatically-dialed, pre-recorded Voice over IP phone calls by telemarketers and prank callers. Such calls have become known as “Voice over IP Spam”, or “SPIT” (Spam over Internet Telephony). As a result, a number of techniques have been developed to try to detect SPIT, as well as other types of unwanted or malicious actions perpetrated via calls (e.g., network abuse, attacks on data-processing systems, etc.).
One such technique utilizes a database of profiles that specify various characteristics of such calls, much like an attack signature database is utilized in an intrusion detection system (IDS). For example, a profile database might contain a profile that indicates that successive calls to multiple telephone extensions of an enterprise from the same caller are likely unwanted calls. As another example, a profile might indicate that a call to a residence during dinner time with suppressed Caller ID information is likely an unwanted call.